toms923, a MATLAB code which evaluates the Pfaffian for a dense or banded skew symmetric matrix, by Michael Wimmer.


The computer code and data files made available on this web page are distributed under the GNU LGPL license.


toms923 is available in a MATLAB version and a Python version.

Related Data and Programs:

test_mat, a MATLAB code which defines test matrices for which the condition, determinant, eigenvalues, inverse, null vectors, P*L*U factorization or linear system solution are already known, including the Vandermonde and Wathen matrix.



  1. Michael Wimmer,
    Algorithm 923: Efficient Numerical Computation of the Pfaffian for Dense and Banded Skew-Symmetric Matrices,
    ACM Transactions on Mathematical Software,
    Volume 38, Number 4, Article 30, August 2012.

Source Code:

Last modified on 12 May 2020.